请高手帮忙用JFreeChart在jsp中显示折线图，或是用java画折线图

[mingyuan20030118]

谢谢大家看贴，我的问题是有关折线图的问题，希望各位能够鼎力相助

现在公司开发一个非常金的管理项目，其中一个模块需要用折线图来显示，但是我实在是不知道该怎么做，柱状图我市可以画出来的，但也只是照猫画虎，通过其他高手在网上的例子画出来的，但是到了折线图这里我就不知道该怎么办了！希望各位同仁相助！小弟在这谢谢了，希望知道或者做过的朋友多提一些意见，或是最好能给出一个折线图的例子！虽然高手是不在乎分数的，但是只要能够解决问题我这200全部奉送上！也可以通过邮箱发给我，也欢迎各位同仁互相交流
QQ：79905370
MSN：[e-mail]
Email: [e-mail]

[zhujj81]

用JSP生成折线图并以图片的方式显示出来，不知道可不可以。现有如下代码，以便共同学习。

<%@ page language="java" contentType="image/jpeg;charset=GB2312"
import="java.util.*,java.awt.*,java.awt.geom.*"
import="java.awt.image.*,com.sun.image.codec.jpeg.*"
%>
<%
int width=600,height=500;
BufferedImage image=new BufferedImage(width,height,BufferedImage.TYPE_INT_RGB);
Graphics g=image.getGraphics();
Graphics2D g2d=(Graphics2D) g;
g.setColor(new Color(240,249,255));
g.fillRect(0,0,width,height);
g.setColor(Color.white);
g.drawRect(10,35,width-20,height-46);
g.setColor(Color.black);
g.setFont(new Font("华文新魏",Font.PLAIN,22));
g.drawString("水果销售情况图表 JSP版（折线图） 网友提供",15,25);
int book_sales[]=new int[5];
for(int i=0;i<book_sales.length;i++){
book_sales[i]=1+(int)(Math.random()*100);
}
String book_title[]={"苹果","香蕉","荔枝","猕猴桃","葡萄"};
Color color[]=new Color[5];
color[0]=new Color(99,99,0);
color[1]=new Color(255,169,66);
color[2]=new Color(33,255,66);
color[3]=new Color(33,0,255);
color[4]=new Color(255,0,66);
g.setFont(new Font("华文行楷",Font.BOLD,16));
g.drawString("销售量",20,50);
g.drawString("水果分类",500,465);
g.setFont(new Font("SanSSerif",Font.PLAIN,12));
int salesValue=0;
for(int i=418;i>0;i-=38){
g.setColor(Color.black);
g.drawString(""+salesValue,36,(i+27));
g.setColor(Color.lightGray);
g.drawLine(80,(i+27),520,(i+27));
salesValue+=10;
}
g.setColor(Color.black);
g.drawLine(80,40,80,445);
g.drawLine(80,445,550,445);
int drawHigh[]=new int[book_title.length];
int drawwidth[]=new int[book_title.length];
for(int i=0;i<book_title.length;i++){
drawHigh[i]=445-(int)(Math.ceil(book_sales[i]*3.8));
drawwidth[i]=110+i*80;
g.setColor(color[i]);
g.fillOval(drawwidth[i]-7,drawHigh[i]-7,14,14);
g.setColor(Color.black);
g.drawString(book_title[i],110+i*80,465);
}
g2d.setXORMode(Color.white);
g2d.setStroke(new BasicStroke(4.0f));
g2d.setPaint(Color.red);
g2d.drawPolyline(drawwidth,drawHigh,book_title.length);
g.dispose();
ServletOutputStream sos=response.getOutputStream();
JPEGImageEncoder encoder=JPEGCodec.createJPEGEncoder(sos);
encoder.encode(image);
%>

[zhaoqiubo]

你可以下载jfreechart的源码,在package org.jfree.chart.demo;内都是它生成各种图表的示例,非常全面;
其中有一个折线图如下:

package org.jfree.chart.demo;

import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Dimension;

import org.jfree.chart.ChartFactory;
import org.jfree.chart.ChartPanel;
import org.jfree.chart.JFreeChart;
import org.jfree.chart.StandardLegend;
import org.jfree.chart.axis.NumberAxis;
import org.jfree.chart.labels.ItemLabelPosition;
import org.jfree.chart.plot.CategoryPlot;
import org.jfree.chart.plot.PlotOrientation;
import org.jfree.chart.renderer.LineAndShapeRenderer;
import org.jfree.data.CategoryDataset;
import org.jfree.data.DefaultCategoryDataset;
import org.jfree.ui.ApplicationFrame;
import org.jfree.ui.RefineryUtilities;

/**
* A simple demonstration application showing how to create a line chart using data from a
* {@link CategoryDataset}.
*
* @author David Gilbert
*/
public class LineChartDemo1 extends ApplicationFrame {

/**
* Creates a new demo.
*
* @param title the frame title.
*/
public LineChartDemo1(String title) {

super(title);

CategoryDataset dataset = createDataset();
JFreeChart chart = createChart(dataset);
ChartPanel chartPanel = new ChartPanel(chart);
chartPanel.setPreferredSize(new Dimension(500, 270));
setContentPane(chartPanel);

}

/**
* Creates a sample dataset.
*
* @return The dataset.
*/
private CategoryDataset createDataset() {

// row keys...
String series1 = "First";
String series2 = "Second";
String series3 = "Third";

// column keys...
String type1 = "Type 1";
String type2 = "Type 2";
String type3 = "Type 3";
String type4 = "Type 4";
String type5 = "Type 5";
String type6 = "Type 6";
String type7 = "Type 7";
String type8 = "Type 8";

// create the dataset...
DefaultCategoryDataset dataset = new DefaultCategoryDataset();

dataset.addValue(1.0, series1, type1);
dataset.addValue(4.0, series1, type2);
dataset.addValue(3.0, series1, type3);
dataset.addValue(5.0, series1, type4);
dataset.addValue(5.0, series1, type5);
dataset.addValue(7.0, series1, type6);
dataset.addValue(7.0, series1, type7);
dataset.addValue(8.0, series1, type8);

dataset.addValue(5.0, series2, type1);
dataset.addValue(7.0, series2, type2);
dataset.addValue(6.0, series2, type3);
dataset.addValue(8.0, series2, type4);
dataset.addValue(4.0, series2, type5);
dataset.addValue(4.0, series2, type6);
dataset.addValue(2.0, series2, type7);
dataset.addValue(1.0, series2, type8);

dataset.addValue(4.0, series3, type1);
dataset.addValue(3.0, series3, type2);
dataset.addValue(2.0, series3, type3);
dataset.addValue(3.0, series3, type4);
dataset.addValue(6.0, series3, type5);
dataset.addValue(3.0, series3, type6);
dataset.addValue(4.0, series3, type7);
dataset.addValue(3.0, series3, type8);

return dataset;

}

/**
* Creates a sample chart.
*
* @param dataset a dataset.
*
* @return The chart.
*/
private JFreeChart createChart(CategoryDataset dataset) {

// create the chart...
JFreeChart chart = ChartFactory.createLineChart(
"Line Chart Demo 1", // chart title
"Type", // domain axis label
"Value", // range axis label
dataset, // data
PlotOrientation.VERTICAL, // orientation
true, // include legend
true, // tooltips
false // urls
);

// NOW DO SOME OPTIONAL CUSTOMISATION OF THE CHART...
StandardLegend legend = (StandardLegend) chart.getLegend();
legend.setDisplaySeriesShapes(true);
legend.setShapeScaleX(1.5);
legend.setShapeScaleY(1.5);
legend.setDisplaySeriesLines(true);

chart.setBackgroundPaint(Color.white);

CategoryPlot plot = chart.getCategoryPlot();
plot.setBackgroundPaint(Color.lightGray);
plot.setRangeGridlinePaint(Color.white);

// customise the range axis...
NumberAxis rangeAxis = (NumberAxis) plot.getRangeAxis();
rangeAxis.setStandardTickUnits(NumberAxis.createIntegerTickUnits());
rangeAxis.setAutoRangeIncludesZero(true);
rangeAxis.setUpperMargin(0.20);
rangeAxis.setLabelAngle(Math.PI / 2.0);

// ****************************************************************************
// * JFREECHART DEVELOPER GUIDE *
// * The JFreeChart Developer Guide, written by David Gilbert, is available *
// * to purchase from Object Refinery Limited: *
// * *
// * http://www.object-refinery.com/jfreechart/guide.html *
// * *
// * Sales are used to provide funding for the JFreeChart project - please *
// * support us so that we can continue developing free software. *
// ****************************************************************************

// customise the renderer...
LineAndShapeRenderer renderer = (LineAndShapeRenderer) plot.getRenderer();
renderer.setDrawShapes(true);

renderer.setSeriesStroke(
0, new BasicStroke(2.0f,
BasicStroke.CAP_ROUND,
BasicStroke.JOIN_ROUND,
1.0f,
new float[] {10.0f, 6.0f},
0.0f)
);
renderer.setSeriesStroke(
1, new BasicStroke(2.0f,
BasicStroke.CAP_ROUND,
BasicStroke.JOIN_ROUND,
1.0f,
new float[] {6.0f, 6.0f},
0.0f)
);
renderer.setSeriesStroke(
2, new BasicStroke(2.0f,
BasicStroke.CAP_ROUND,
BasicStroke.JOIN_ROUND,
1.0f,
new float[] {2.0f, 6.0f},
0.0f)
);

renderer.setItemLabelsVisible(true);
renderer.setPositiveItemLabelPosition(new ItemLabelPosition());
renderer.setNegativeItemLabelPosition(new ItemLabelPosition());
// OPTIONAL CUSTOMISATION COMPLETED.

return chart;
}

/**
* Starting point for the demonstration application.
*
* @param args ignored.
*/
public static void main(String[] args) {

LineChartDemo1 demo = new LineChartDemo1("Line Chart Demo");
demo.pack();
RefineryUtilities.centerFrameOnScreen(demo);
demo.setVisible(true);

}

}